Inductive regulator for coarse and fine regulation



y 1940- R. BAUER 2,201,642

INDUCTIVE REGULATOR FOR COARSE AND FINE REGULATION Filed Nov. 11. 19s? Fig.2

Fig. 6

I 1 \fi @mnunm 4 33 2 6 7 9 30 as W LB?) 15 L I Patented May 21, 1940'- INDUCTIVE REGULATOR FOR OOARSE AND FINE REGULATION Rudolf Bauer, Berlin-Siemenutadt, Germany, assignor to Siemens a Balske, Aktiengeaelischaft, Siemensstadt, near Berlin, Germany, a corporation of Germany Application November 11, 1937, Serial No. 114,072

- In Germany December 18, 1938 3 Claims. (c1. 171-119) The present invention relates to inductive regulator for coarse and fineregulation.

If any finely graded variable alternating voltage is to be taken from an alternating-cur-' rent supply circuit, devices are, as a rule, employed which possess a regulator for coarse regulation and one for fine regulation. The latter are preferably designed in the form of transformers with a secondary winding whose number of turns is'variable, the number of the secondary turns being varied by movinga contact which varies the number of turns of the tapped winding. Such a device particularly employed for the above-mentioned purpose is shown in Fig. 1 in diagrammatic form.

In Figs. 2 to 5 are shown some embodiments of the invention 'of'diagrammatic form, and Fig. 6 shows, partly in vertical section, a structural embodiment of my invention shown diagrammatically in Fig. 4.

Across the-terminals l and 2 of the supply circuit is connected aninductive coarse regulator 3 which in the arrangement shown in Fig. 1 consists of a single winding arranged on an iron core not shown. To a portion of the winding 3 is connected a fine regulator l which may also consist of a single winding arranged on an iron core. Contacts 5 and 0 which may be moved along the windings 3 and l are connected to the output terminals 1 and 8 intended for a current consuming device 9. 'In this manner the corresponding variable parts of the coarse and fine regulator are connected in series so that also the winding of the fine regulator 4 must be rated for -the' maximum value of the current intensity of the current consuming device.

In the known devices the degree of regulation depends upon the number of turns of the wind ing of the fine regulator. However, since the cross-sectionwof' the wire must be dimensioned for suming device, which contacts must be therefore suitably dimensioned and which represent variable contact resistances.

The above-mentioned drawbacks may be removed according to the invention by providing means for inductively transferring the variable voltage tapped off from the fine regulator to the circuit including the current consuming device and connected to the coarse regulator. this case the fine regulator may be connected to the primary or the secondary side of the coarse regulator or to a portion thereof. A particularly simple arrangement is obtained if the coarse regulator is employed at the same time as a fine regulator and is consequently provided with an additional sliding contact serving to tap off a voltage to be employed for the fine regulation.

In Figs. 2 to 4 the coarse regulator is designed as an inductive regulator with a primary winding I 0 connected to the terminals l and 2 and a secondary winding Ii inductively coupled therewith. In the embodiment shown in Fig. -2 is provided an inductivefine regulator I! which ,1! of the coarse regulator. However, the fine regulator might also be, connected to the primary side of the coarse regulator. A contact it which extends to the output terminal 8 for the current i I The high-voltage winding I! of this auxiliary transformer is at one end connected to a fixed point ll of line regulator winding l2 and at the other end toa contact II slidably arranged on winding l2. The point of connection is preferably arranged in the center oithe winding l2.

When the terminals I and 2 are connected to the number of turns or contacts of the winding II by displacing the contact It. If the contact I1 is in the center of the fine regulator winding i2, i. e, at the point II, the. voltage supplied to the transformer winding II is equal to zero. By displacing the contact II to the left or the right the resulting voltage is transmitted inductively in the one or the other sense to the low-voltage winding II in a number of steps corresponding to the number of turns of the fine. regulator winding it. In this case, the voltage transferred to suming device 9 is reduced in accordance with the transformation ratioof the transformer l4, l5. Depending upon the position of the contact IT with respect to point It the voltage acts in an additive or subtractive manner so that the voltage across the terminals I, I to be tapped off may be gradually increased or decreased by displacing the contact II of the fine regulator. In this case the arrangement of the tapping point It in the center of the fine regulator winding has the particular advantage that the transformer l4, l5 may be rated only for half the total voltage applied to the fine regulator.

The degree of regulation may be increased substantially at will by the arrangement according to the invention byselecting a correspondingly high transformation ratio for the transformer l4, l5.

In this manner the current intensity in the high-voltage winding I5 is accordingly reduced so that the fine regulator 12 may be wound with thin wire, i. e., with a correspondingly higher number of turns.

In the arrangement shown in Fig. 3 is provided a fine regulator having two separate windings l8, IS. The primary winding II is connected as in the embodiment shown in Fig. 2 to a portion of the secondary winding ll of the coarse regulator and the center 2| of the secondary winding i9 is connected to that end of the secondary winding II of the coarse regulator to which also the primary winding ll of the fine regulator is connected. Between the center 2.

.traverses the smaller portion of the transformer winding 22. In this manner similarly as in the arrangement shown in Fig. 2 a voltage is induced in the smaller portion of the winding 22, corresponding to the fine regulator voltage tapped off by the sliding contact 2|. The degree of regulation may also be in this case chosen at will by correspondingly selecting the transformation ratio of the winding portions of the transformer 22.

In the embodiments of the invention shown in Figs. 4 and 5 a special fine regulator, such as l2 or l8, I! in Figs. 2 or 3, is dispensed with and the coarse regulator is employed simultaneously as a fine regulator. To this end, two'separate contacts 13 and 24 slidably arranged on the secondary winding II are provided in the embodiment according to Fig. 4.

In this case, the contact I! connected to the output terminal 8 serves as in the above-described embodiments to effect a coarse regulation and the contact 24 to effect a fine regulation. Further, as in Fig. 2, an auxiliary transformer I4, I! is employed, which has one terminalof its high voltage primary connected to slide 24 and the other terminal to a fixed point 25 of winding ll.

Thus a voltage serving-to effect a fine regulation is tapped off by the sliding contact 24 and supplied to the high-voltage winding I! of the auxby rotating the worm shaft.

iliary transformer whose low-voltage winding l4, asinFlg.2,isconnectedatoneendtotheend point of the secondary winding II and at the other end to the output terminal 1.

The arrangement shown in Fig. 5 differs from that in Fig. 4 merely y the use of an autotransformer of a single winding 26 instead of the transformer II, II in Fig. 4. In'both cases, Fig. 4 as well as Fig. 5, as in the arrangement according to Fig. 2a fine regulating voltage tapped ofl from the points 24, 25 of the regulator winding I l and 24 respectively is transmitted additively or subtractively to the current consuming device'circuit depending upon the position of the sliding contact 24.

with such an arrangement the degree of regulation is, of course, dependent upon the number ofstepsofthecoarseregulator. Ifnis the number of turns of the regulating winding I i and 2' respectively, the transformation ratio m of the transformer l4, I5 is choun smaller than 11. Each of the n coarse steps may be then subdivided again into 11: fine steps by displacing the fine regulating contact 24 along the regulator winding soasto result inatotal ofmm fine steps.

Fig. 6 shows the construction of an inductive regulator according to the invention, the arrangement and the connection being the same as showninFlg.4. 'Onabase 21 connected to a bearing plate 2! bymeans of columns 24 is secured a ring core ll shown in cross-section and having a secondary winding ll wound on top of a primary winding II. In the plates 21 and 2! is mounted a shaft II and on the latter is jour- "nailed a hollow shaft 22. An arm 34 is secured to hollow shaft 22 but insulated therefrom by a disc 22. The arm 24 carries a stud 25 to which are resiliently secured rollers I! in such a manner that they roll as brushes on the winding H.

A contact brush 26 which is insulatedly secured to the plate 2! serves to connect the contact arm 34 to the terminal 8 not shown.

To the shaft II is insulatedly secured a second contact arm 31 at the end of which a roller 24 is resiliently mounted so that it is pressed against the same winding II. A brush ll insuiatedly securedtothebaseplateflservestoreceivecurrent from the contact arm TI to be conducted to winding II of Pig. 4.

"To the hollow shaft 32 is secured a worm wheel'- 2! which is in cut with a worm 4! so that the coarse regulating contact I! may be adjusted 7 To adjust the fine regulating contact 24 the shaft II which is shown brokenawayinFlg.6mayberotatedinany suitable manner not shown here. The remainingelementsinFig. Gmaybeassumedasbeing provided and connected in the manner shown in Fig. 4.

What is claimed is:

, 1.. An arrangement for supplying from an alternating current source to a consumer a voltage widely variable in fine steps, including a main variable voltage transformer connected to the current source and having an output winding provided with a'fixed end terminal and a stepwise variable terminal so as to derive variable output voltages from said winding in a given number of 11 steps, said consumer being connected to said fixed and to said variable terminal, an auxiliary transformer having one terminal of it high voltage primary winding fixedly connected to themid-point of said main transformer output and its other terminal variably connected to said output winding, said auxiliary transformer having its low voltage secondary winding connected in circuit with said consumer, the transformation ratio m of said auxiliary transformer being not greater than the step number n of said main transformer.

2. An arrangement for supplying from an alternating current source to a consumer a voltage widely variable in fine steps, including a main variable voltage transformer having its primary winding connected to said source and having a secondary winding provided with a fixed and a stepwise variable output terminal to derive variable voltages from said winding in a given number of n steps, said consumer being connected to said fixed and tosaid variable terminal, and an auxiliary transformer having one terminal of its high voltage primary winding fixedly connected to the mid-point of said secondary main transformer winding and its other terminal stepwise variably connected to said latter windtransformation ratio m of said auxiliary transformer being not greater than the step number n of said main transformer.

3. An arrangement for supplying from an alternating current source to a consumer a voltage widely variable in fine steps, including an autotransformer having fixed outer terminals connected to the current source and an inner terminal variable in'a'given number of n steps, said consumer being connected to one of said fixed terminals'and to said variable terminal for deriving a variable voltage therefrom, and an auxiliary transformer having one of its high voltage primary terminals fixedly connected to the winding mid-point of said autotransformer and its other terminal variably connected to said winding, said auxiliary transformer having its low voltage sec- 'ondary winding connected in circuit with said consumer, the transformation ratio m of said auxiliary transformer being not greater thanthe step number n of said autotransformen.

RUDOLF BAUER. 

